Management of ankle deformities in multiple hereditary osteochondromata

Nine patients with multiple hereditary osteochondromata underwent ankle surgery for valgus deformity. The indications for operation included pain from trauma of the prominent masses, pain in the ankle joint associated with the deformity, limited ankle motion, and undesirable cosmesis. The procedures included excision of osteochondromata, fibular lengthening, and medial tibial hemiepiphyseal retardation by inserting staples. Excision of osteochondromata as an isolated procedure relieved pain and improved cosmesis but did not alter the tibiofibular length discrepancy or the ankle valgus. Lengthening of the fibula and medial tibial hemiepiphyseal stapling, alone or in combination, corrected the valgus deformity of the ankle. At final follow-up (mean 43 months), no patient had pain or functional impairment.     

The treatment of ankle valgus by surface epiphysiodesis

Progressive ankle valgus in childhood requiring surgical correction is usually because of paralytic disease or conditions that produce a short distal fibula such as multiple exostoses or both. Surface epiphysiodesis of the distal medial tibial physis was used to correct valgus deformity in ten ankles in seven patients. This procedure has been found to be a simple and effective method of treatment. Measurement of the degree of valgus and calculation of the remaining growth of the distal tibial physis are recommended to determine whether this procedure will be effective. It is most often indicated in the presence of moderate valgus in children aged 11 to 14 years.     

Comprehensive treatment of late-onset tibia vara

BACKGROUND: Late-onset tibia vara (Blount disease) can be difficult to treat because of frequent morbid obesity and associated deformities, including distal femoral varus, proximal tibial procurvatum, and distal tibial valgus, that contribute to lower extremity malalignment. We present a comprehensive approach that addresses all components of the deformity and allows restoration of the anatomic and mechanical axes. METHODS: Fifteen consecutive patients (nineteen lower extremities) with late-onset tibia vara were managed with this comprehensive approach. The mean age of the patients at the time of surgery was 14.9 years, and the mean weight was 113 kg. Standing anteroposterior and lateral radiographs were made preoperatively and at the time of the final follow-up. Preoperatively, the mean mechanical axis deviation was 108 mm, the mean lateral distal femoral angle was 95 degrees , and the mean mechanical medial proximal tibial angle was 71 degrees . In all nineteen extremities, the proximal tibial varus deformity was corrected by means of a valgus osteotomy and application of an Ilizarov ring external fixator. Distal femoral varus was corrected by means of either hemiepiphyseal stapling or valgus osteotomy with blade-plate fixation in thirteen of the nineteen extremities. Distal tibial valgus was treated either with hemiepiphyseal stapling or with varus osteotomy and gradual correction with use of the Ilizarov external fixator in eleven of the nineteen extremities. RESULTS: After a mean duration of follow-up of 5.0 years, the mean mechanical axis deviation had improved to 1 mm (range, 20 to -30 mm), the lateral distal femoral angle had improved to 87 degrees (range, 83 degrees to 98 degrees), and the mechanical medial proximal tibial angle had improved to 88 degrees (range, 83 degrees to 98 degrees ). The mean time required for correction of the proximal tibial varus deformity was thirty-one days, and the external fixator was removed at a mean of 4.5 months postoperatively. All patients had development of one or more superficial pin-track infections (mean, 1.9 pin-site infections per patient). No wound infections, nonunions, or neurovascular complications occurred. Eighteen of the nineteen extremities were pain-free at the time of the final follow-up. CONCLUSIONS: This comprehensive approach allowed restoration of the mechanical and anatomic axes of the lower extremity in patients with late-onset tibia vara, resulting in a resolution of symptoms as a result of normalization of the weight-bearing forces across the knee and ankle. We believe that this approach will decrease the risk of early degenerative arthritis of the knee.     

Outcome of hemiepiphyseal stapling for late-onset tibia vara

BACKGROUND: The results of hemiepiphysiodesis for the treatment of late-onset tibia vara have been reported to be favorable, but the technique requires careful timing and an accurate estimation of skeletal age. Hemiepiphyseal stapling does not require a careful estimation of skeletal age, and it has been reported to yield good results with low morbidity. However, we are not aware of any study evaluating the intermediate-term radiographic results or complications of this procedure. METHODS: Twenty-six patients with thirty-three extremities with late-onset tibia vara were treated with proximal tibial hemiepiphyseal stapling. Fourteen extremities had substantial concomitant distal femoral varus and also had hemiepiphyseal stapling of the distal part of the femur. Eighteen patients (twenty-three involved extremities) had juvenileonset tibia vara and eight patients (ten involved extremities) had adolescent-onset tibia vara. The mean age at the time of stapling was 11.8 years. The mean duration of follow-up was 3.8 years. We reviewed standardized standing radiographs to determine the mechanical axis deviation, the medial proximal tibial angle, the lateral distal femoral angle, and the zone of the knee through which the mechanical axis passed. RESULTS: The mean mechanical axis deviation improved from 58 mm (range, 27 to 157 mm) preoperatively to 22 mm (range, -33 to 117 mm) at the time of the last follow-up, and the mean medial proximal tibial angle improved from 77 degrees (range, 50 degrees to 85 degrees ) to 85 degrees (range, 48 degrees to 95 degrees ). In the fourteen lower extremities in which distal femoral hemiepiphyseal stapling was performed, the mean lateral distal femoral angle improved from 96 degrees (range, 92 degrees to 100 degrees ) to 86 degrees (range, 79 degrees to 97 degrees ). At the time of the final follow-up, seven extremities were considered to be in moderate varus; four, in mild varus; twenty, in normal alignment; and two, in valgus. No differences in radiographic outcome were noted between the juvenile and adolescent forms of tibia vara. Only one of the four extremities with severe preoperative varus was corrected to normal alignment; the remaining three were left with moderate varus. CONCLUSIONS: Hemiepiphyseal stapling of the lateral aspect of the proximal tibial physis and, as needed, the lateral aspect of the distal femoral physis is safe and effective in children with late-onset tibia vara if the physes are sufficiently open and the varus deformity is mild to moderate. Hemiepiphyseal stapling is particularly effective in patients who are ten years of age or younger. LEVEL OF EVIDENCE: Therapeutic Level IV.     

Management of knee deformity in hereditary multiple exostoses: a case report

This article discusses a case of hereditary multiple exostoses suffered by a female patient. The typical clinical and radiographic signs and symptoms are presented. Particular attention is focused on management of a specific knee complaint caused by this condition and the epidemiology of lower limb dysfunction associated with multiple exostoses. Knee deformity in patients with multiple hereditary exostoses presents primarily as genu valgum caused by valgus angulation of the tibia. Changes in ratio of the fibular length to the tibial length are also evident in such patients. The natural history of these deformities is progression with variable weakness, functional impairment, and cosmetic deformity of the extremity. Since malignant degeneration of exostoses to chondrosarcoma is a possibility, management of biomechanical complaints requires continued re-evaluation, rehabilitative techniques and surgical referral if indicated.     

Primary hypophosphatemic rickets. Effect of oral phosphate and vitamin D on growth and surgical treatment

Failure to diagnose and treat hypophosphatemic rickets during childhood resulted in stunted growth and progressive deformities of the lower limb. When the deformities were treated surgically, recurrent deformity and non-union of osteotomies developed, and further major opeative procedures were required to remedy these complications. Treatment from early childhood with oral phosphate and vitamin D improved the rate of growth and controlled the progression of bowleg deformity. Residual varus deformity was corrected by osteotomy through the proximal tibial metaphysis at skeletal maturity, when the results were predictable. Genu valgum deformity was corrected by stapling the medial part of the distal femoral epiphysis prior to skeletal maturity. With early postoperative mobilization and adequate medication, the complications of delayed tibial union and failure to correct the femoral valgus deformity were avoided.     

Ankle valgus and clubfeet.

Congenital equinovarus is a complex deformity that involves the ankle as well as the foot. Although equinus is the obvious and presenting ankle deformity that is typically addressed with serial manipulation, casts, and surgery, ankle valgus is a more insidious and often overlooked problem that evolves with growth. With a high prevalence (67% in this series), it may, in some cases, ameliorate the effects of residual hindfoot varus. More commonly, it may result in prominence of the medial malleolus, lateral shift of the ground reactive forces, compression of the lateral portion of the distal tibial epiphysis, fibular impingement, and excessive shoe wear. If mistaken for hindfoot valgus ("overcorrected clubfoot"), inappropriate hindfoot surgery may result. Although one may temporize with orthoses, definitive treatment options include medial malleolar epiphysiodesis or, in mature patients, supramalleolar osteotomy. We recommend a weight-bearing anteroposterior radiograph of the ankles in any patient presenting with valgus and suspected of having overcorrected congenital equinovarus, particularly if surgical intervention is being contemplated. If valgus deformity is noted in the ankle, hindfoot surgery may be contraindicated.     

Treatment of genu valgus deformity in congenital absence of the fibula

Twenty patients with Syme amputation for congenital absence of the fibula and genu valgus deformity were followed until skeletal maturity. Radiographs were analyzed for genu valgus, mechanical axis, tibial angulation, and the condylar height ratio. This ratio was determined by measuring the greatest perpendicular height from the physis to the joint line and dividing the lateral height by the medial height. A smaller value represented more marked lateral condylar hypoplasia. The presence of medial tibial angulation and the degree of lateral femoral condylar hypoplasia correlated with the degree of genu valgus. Two of three patients who had proximal tibial osteotomies required multiple procedures for recurrent deformity. Medial distal femoral physeal stapling corrected the deformity in five of six limbs. The procedure is simple, allows immediate weightbearing in the prosthesis postoperatively, and has low morbidity. Patients should be followed closely until skeletal maturity. Osteotomy performed before skeletal maturity can result in recurrence of genu valgus deformity.     

Hereditary multiple exostoses: one center's experience and review of etiology

Hereditary multiple exostosis is a genetic disorder characterized by multiple osteochondromas that can cause pain, deformity, and potential malignant degeneration. Linkage analysis has identified a family of EXT genes which, if mutated, can lose heterozygosity and potentially cause osteochondromas. A database was established of 43 patients with hereditary multiple exostoses treated at a tertiary pediatric healthcare system. Twenty patients had a known family history of the disorder. All patients were diagnosed between birth and 13 years. Symptoms or deformity were observed in the forearms of 29 patients, the knees of 37 patients, and the ankles of 28 patients. Valgus knee deformity related to hereditary multiple exostoses, previously reported to be attributable to proximal tibial changes alone, resulted from proximal tibial or distal femoral valgus deformities in this series. Twenty-seven patients required between one and five surgeries to address their lesions. No patient had malignant degeneration of an osteochondroma; however, three patients had first-degree relatives with transformation of an osteochondroma to chondrosarcoma. This database now may be a resource for additional analysis. By correlating specific genetic mutations with clinical manifestations, it may be possible to stratify patients into subtypes of hereditary multiple exostoses and identify genetic markers associated with malignant degeneration.     

Risk factors for ankle valgus in children with hereditary multiple exostoses: a retrospective cross-sectional study

PurposeThe aim of this study was to identify risk factors for ankle valgus in children with hereditary multiple exostoses (HME).MethodsWe retrospectively reviewed the medical records of patients with HME who were examined at our hospital between 2010 and 2020. Patients’ age and sex were recorded along with radiographic variables including mechanical axis deviation (MAD), mechanical lateral distal tibia angle (LDTA), fibula/tibia length ratio (F/T); distal fibula station according to Malhotra’s classification, location of exostoses at the ankle joint and fibular neck/physis width (N/P) ratio, which were measured from radiographs. Binary logistic regression analysis was performed to identify significant independent risk factors for ankle valgus.ResultsThere were 61 children (20 girls and 41 boys; 122 ankles) who met the inclusion criteria. The mean age was 10.4 years (sd 3.4) and mean LDTA was 83° (sd 7°). Ankle valgus was found in 64 ankles (52%). In addition to younger age, exostoses involving the lateral aspects of the distal tibial and the medial aspect of the distal fibula (odds ratio (OR) = 4.091; 95% confidence interval (CI) 1.065 to 15.712; p = 0.040), F/T ratio < 0.96 (OR = 4.457; 95% CI 1.498 to 13.261; p = 0.007) and N/P ratio > 1.6 (OR = 2.855; 95% CI 1.031 to 7.907; p = 0.043) were associated with an increased risk of developing ankle valgus, while sex and MAD were unrelated to its occurrence.ConclusionYoung age, exostoses involving both the distal tibia and fibula, the F/T ratio < 0.96 and fibular N/P width ratio > 1.6 seemed to be risk factors of developing ankle valgus.Levels of evidencePrognostic studies, IV     

Infantile tibia vara: Treatment of Langenskiold stage IV

An eight year old girl presented with a progressively increasing deformity of the left proximal tibia since last 2 years. She had no history of trauma, fever and swelling of left knee. There were no obvious signs of rickets/muscular dystrophy. She had 25 degrees of tibia vara clinically with lateral thrust and a prominent fibular head. The radiograph of left knee revealed tibia vara with medial beaking and a significant depression of the medial tibial epiphysis and metaphysis. A computed tomography (CT) scan revealed significant depression of the medial tibial epiphysis but no bony bar in the physis or fusion of the medical tibial epiphysis. There was a posterior slope in addition to the medial one. She was treated with elevation of the medial tibial hemiplateau with subtuberosity valgus derotation dome osteotomy. She also underwent a lateral proximal tibial hemiphysiodesis (temporary stapling). A prophylactic subcutaneons anterolateral compartment fasciotomy was also performed. All osteotomies united in 2 months. All deformities were corrected and she regained a knee range of 0 to 130 degrees. At final followup (4 years), there was no recurrence of varus deformity, knee was stable, with 1cm of leg length discrepancy. In Langenskiold stage IV tibia vara, elevation of medial tibial plateau, a subtuberosity valgus derotation osteotomy and a concomitant lateral hemiephiphysiodesis has given good results.     

The association between ulnar length and forearm movement in patients with multiple osteochondromas

PURPOSE: To determine the relationship between the length of the ulna as a proportion of height (proportional ulnar length [PUL]), forearm and wrist ranges of motion, and degree of observable deformity in people with hereditary multiple exostoses. METHODS: One hundred forty-two people with hereditary multiple exostoses were examined; 35 were under the age of 15 years and therefore were presumed to be skeletally immature. Elbow, forearm, and wrist motion were measured, and the radius and ulna were palpated for osteochondromas. Ulnar length was estimated as a proportion of height (PUL) in skeletally immature subjects. The relationships between total active motion, number of palpable osteochondromas, and proportional length were examined for one randomly selected limb from each subject. RESULTS: A negative correlation was found between the number of palpable osteochondromas and range of forearm rotation. The degree of forearm motion in those under the age of 15 years was directly related to PUL and indirectly related to the number of palpable osteochondromas. Children whose PUL is within the normal range have a normal range of motion. CONCLUSIONS: In a child with hereditary multiple exostoses affecting the forearm, the PUL is associated with the range of movement and deformity, and it can be a useful adjunct in deciding the appropriate management.     

Ankle Deformity Secondary to Acquired Fibular Segmental Defect in Children

Background

The authors report the long-term effect of acquired pseudoarthrosis of the fibula on ankle development in children during skeletal growth, and the results of a long-term follow-up of Langenskiold''s supramalleolar synostosis to correct an ankle deformity induced by an acquired fibular segmental defect in children.

Methods

Since 1980, 19 children with acquired pseudoarthrosis of the fibula were treated and followed up for an average of 11 years. Pseudoarthrosis was the result of a fibulectomy for tumor surgery, osteomyelitis of the fibula and traumatic segmental loss of the fibula in 10, 6, and 3 cases, respectively. Initially, a Langenskiold''s operation (in 4 cases) and fusion of the lateral malleolus to the distal tibial epiphysis (in 1 case) were performed, whereas only skeletal growth was monitored in the other 14 cases. After a mean follow-up of 11 years, the valgus deformity and external tibial torsion of the ankle joint associated with proximal migration of the lateral malleolus needed to be treated with a supramallolar osteotomy in 12 cases (63%). These ankle deformities were evaluated using the serial radiographs and limb length scintigraphs.

Results

In all cases, early closure of the lateral part of the distal tibial physis, upward migration of the lateral malleolus, unstable valgus deformity and external tibial torsion of the ankle joint developed during a mean follow-up of 11 years (range, 5 to 21 years). The mean valgus deformity and external tibial torsion of the ankle at the final follow-up were 15.2° (range, 5° to 35°) and 10° (range, 5° to 12°), respectively. In 12 cases (12/19, 63%), a supramalleolar corrective osteotomy was performed but three children had a recurrence requiring an additional supramalleolar corrective osteotomy 2-4 times.

Conclusions

A valgus deformity and external tibial torsion are inevitable after acquired pseudoarthrosis of the fibula in children. Both Langenskiöld supramalleolar synostosis to prevent these ankle deformities and supramalleolar corrective osteotomy to correct them in children are effective initially. However, both procedures cannot maintain the permanent ankle stability during skeletal maturity. Therefore any type of prophylactic surgery should be carried out before epiphyseal closure of the distal tibia occurs, but the possibility of a recurrence of the ankle deformities and the need for final corrective surgery after skeletal maturity should be considered.     

Valgus deformity of the ankle following harvesting of a vascularized fibular graft in children

Progressive valgus ankle deformity is a problematic postoperative donor-site morbidity of a vascularized fibular graft in children. To prevent this complication, tibiofibular metaphyseal synostosis (the Langenski?ld procedure) has been recommended. The authors objectively evaluated the preventive and therapeutic effects of this procedure on five children who had received free vascularized fibular grafts. Their average age at the time of operation was 3 years (range: 1 to 9 years). The Langenski?ld procedure was performed primarily in four patients, and not in one patient. The anteroposterior (A-P) mortise angle and the empirical axis of the donor-site ankle were measured radiographically. With regard to the A-P mortise angle, four of five patients showed valgus with a mild lateral wedging of the distal tibial epiphysis. The patient who did not receive the operation showed the largest A-P mortise angle and mild osteoarthritic changes. The empirical axis exceeded normal range in all of the five patients. These observations indicated that valgus deformity of the ankle in children after harvesting a vascularized fibular graft is inevitable, even if the Langenski?ld procedure is performed. The procedure can delay the ankle valgus. The authors recommend close follow-up of the children who receive the Langenski?ld procedure after harvesting a vascularized fibular graft.     

Correction of ankle valgus by hemiepiphysiodesis using the tension band principle in patients with multiple hereditary exostosis

Background

Ankle valgus is a common deformity in patients with multiple hereditary exostoses (MHE) and a potential risk factor for early degenerative arthritis. In children, medial hemiepiphysiodesis of the distal tibia is a relatively simple surgical technique used to correct this deformity. We present here the first results of applying this procedure using the eight-Plate guided growth system (eight-Plate) for growth guidance.

Methods

Between 2006 and 2011 we performed hemiepiphysiodesis of the distal medial tibia in 30 ankles of 18 children with MHE using the eight-Plate. Weight-bearing total leg radiographs were obtained preoperatively, during follow-up and at the time of implant removal or when the distal tibial physis had closed. The lateral distal tibia angle (LDTA) was measured and fibular shortening assessed using the Malhotra classification. To evaluate the effect of hemiepiphysiodesis, we correlated the LDTA with age.

Results

The mean age at time of surgery was 12.6 (range 9.5–15.0) years, and the mean preoperative LDTA was 76.9° (range 68.5°–83.5°). During follow-up, the implant was removed in 12 extremities and the physis had closed in 18 extremities. The mean LDTA at the time of implant removal or at closure of the physis was 83.6° (range 76.5°–90.0°). Mean correction of LDTA was 6.9° after a mean follow-up period of 22 (range 3–43) months. During follow-up, no changes in the Malhotra classification were found in any of the patients. Correction of the valgus deformity of the ankle was significantly correlated (r = ?0.506) (p = 0.004) with age in all patients.

Conclusion

Temporary medial hemiepiphyseodesis of the distal tibia seems to be an effective strategy for correcting ankle valgus in children with MHE. Timing of the intervention is, however, of importance. Hemiepiphyseodesis alone has no effect on the Malhotra classification.

Level of evidence

IV, retrospective review.

     

The Taniguchi classification in cases of multiple cartilaginous exostoses]

27 patients treated surgically at Child Orthopaedic Clinic of Pomeranian Medical Academy between 1974-1996 for multiple cartilaginous exostosis (Aclasia Diaphysealis Keith) were classified into three groups according to the Taniguchi classification. This classification is based on whether multiple cartilaginous exostoses are present on distal forearm. Group I--no involvement of the distal forearm (n = 2), in group II involvement of the distal forearm without shortening of either bone (n = 7) was stated. Group III consists of members with involvement of the distal forearm with shortening the radius or the ulna (n = 18). Groups were compared with regard to: number of lesions, distribution of exostoses in different body areas, age of onset of the Keith disease, height of children, presence of valgus deformity of the ankle, dislocation of the radial head and presence of exostoses around hip area. This classification should be useful in estimating severity of Keith disease, identifying cases at high risk for complications like dislocation of the radial and malignant transformation.     

Correction and lengthening for deformities of the forearm in multiple cartilaginous exostoses

Background Multiple cartilaginous exostoses cause various deformities of the epiphysis. In exostoses of the ulna, the ulna is shortened and the radius acquires varus deformity, which may lead to dislocation of the radial head. In this study, we present the results of exostoses resection, with correction and lengthening with external fixators for functional and cosmetic improvement, and prevention of radial head dislocation. Methods We retrospectively reviewed seven forearms of seven patients who had deformities of the forearm associated with multiple cartilaginous exostoses. One patient had dislocation of the radial head. Operative technique was excision of osteochondromas from the distal ulna, correction of the radius, and ulnar lengthening with external fixation up to 5 mm plus variance. We evaluated radiographs and the range of pronation and supination. Furthermore, we conducted a follow-up of ulnar length after the operation. Results Dislocation of the radial head of one patient was naturally reduced without any operative intervention. At the most recent follow-up, six of the seven patients showed full improvement in pronation–supination. Ulnar shortening recurred with skeletal growth of four skeletally immature patients; however, it did not recur in one skeletally mature patient. Overlength of 5 mm was negated by the recurrence of ulnar shortening about 1.5 years after the operation. Conclusions We treated seven forearms of seven patients by excision of osteochondromas, correction of radii, and gradual lengthening of ulnas with external fixators. The results of the procedure were satisfactory, especially for function of the elbow and wrist. However, we must consider the possible recurrence of ulnar shortening within about 1.5 years during skeletal growth periods in immature patients.     

Osteochondrosis of the medial malleolar epiphysis: A case report and review of the literature

IntroductionOsteochondrosis is characterized by a disturbance of enchondral ossification in skeletally immature patients and should be investigated in children having a history of persistent foot and ankle pain. Involvement of the medial malleolar epiphysis is rarely reported.Presentation of caseWe describe the case of a sporty 12-year-old male with osteochondrosis of the left medial malleolar epiphysis treated with a conservative management.DiscussionCalcanear, navicular and metatarsal apophysis are the most common locations for osteochondrosis in ankle and foot. Anyway other osteochondrosis should be excluded. Medial malleolar osteochondrosis is occasionally described. We performed a review of the relevant literature and we summarized clinical aspects, radiological characteristics and reported management of this painful and probably underestimated condition.ConclusionMedial malleolar osteochondrosis is a rare but well recognized condition. Only seven cases are described in literature.     

Osteochondromas of the distal aspect of the tibia or fibula. Natural history and treatment

BACKGROUND: There is little information on the natural history or treatment of osteochondromas arising from the distal aspect of either the tibia or the fibula. It is believed that there is a risk of deformation of the ankle if these exostoses are left untreated or if the physis or neurovascular structures are injured during operative intervention. METHODS: We reviewed the records of twenty-three patients who had been treated for osteochondroma of the distal aspect of the tibia or fibula between 1980 and 1996. Four of the patients had hereditary multiple cartilaginous exostoses. There were seventeen male and six female patients, and the average age at the time of presentation was sixteen years (range, eight to forty-eight years). RESULTS: Preoperative radiographs showed evidence of plastic deformation of the fibula in eleven patients who had a large osteochondroma. Four patients elected not to have an operation. The tumor was excised in nineteen patients. Postoperatively, all nineteen patients had a Musculoskeletal Tumor Society score of 100 percent for function of the lower extremity with pain-free symmetrical and unrestricted motion of the ankle at the latest follow-up examination. Partial remodeling of the tibia and fibula gradually diminished the asymmetry of the ankles in all nineteen operatively managed patients; however, the remodeling was most complete in the younger patients. Pronation deformities of the ankle did not change after excision of the tumor. Complications of operative treatment included four recurrences (only three of which were symptomatic), one sural neuroma, one superficial wound infection, and one instance of growth arrest of the distal aspects of the tibia and fibula. CONCLUSIONS: Osteochondromas of the distal and lateral aspects of the tibia were more often symptomatic than those of the distal aspect of the fibula; they most commonly occurred in the second decade of life with ankle pain, a palpable mass, and unrestricted ankle motion. Untreated or partially excised lesions in skeletally immature patients may become larger and cause plastic deformation of the tibia and fibula and a pronation deformity of the ankle. Ideally, operative intervention should be delayed until skeletal maturity, but, in symptomatic patients, partial excision preserving the physis may be necessary for the relief of symptoms and the prevention of progressive ankle deformity. However, partial excision is associated with a high rate of recurrence, so a close follow-up is required. Skeletally mature patients who are symptomatic may require excision of the tumor.     

Multiple hereditary osteochondromata

Multiple hereditary osteochondromata is a disorder consisting of multiple projections of bone (exostoses) capped by cartilage. The lesions are most numerous in the metaphyses of long bones but may appear on diaphyses of long bones and on flat bones and vertebrae. The transmission is autosomal dominant. Sarcomatous transformation is uncommon and probably occurs in fewer than 1% of patients. The more common indications for surgical excision of lesions are pain, growth disturbance, compromised joint motion, cosmesis, and secondary impingement of tendon, nerve, or vessel. Excision of the lesions is effective in relieving pain, improving cosmesis and joint motion, and removing secondary impingement of tendon, nerve, or vessel, and may retard or prevent progressive disturbance of osseous growth. Wrist and ankle deformities are often associated with relative shortening and bowing of the ulna and fibula, respectively; tilt and tapering of the distal radial and tibial epiphyses; and distal radioulnar and tibio-fibular diastasis. These deformities can be effectively treated by ulnar and fibular lengthening combined with hemiphyseal stapling of the distal radius and tibia. Progressive genu valgum is well corrected by placement of staples over the medial side of the physis of the distal femur or proximal tibia or both.